Back on my first job in retail, at a grocery store, I had similar issues with tobacco customers even though I was a smoker at the time. I didn't chew tobacco, or dip, or snuff, and didn't know all their lingo.
I imagine some smokers are still insisting on calling certain brands things like Lights and Ultra Lights, even though this terminology was banned a number of years ago. Generally, "Lights" are gold logo, and "Ultra Lights" are silver or white logo, though this can vary a bit by brand.
There are even more varieties of most brands than there were 10+ years ago when I was a smoker, and before more descriptive terms were banned.
These things are hard for everyone in a job like yours, keep that in mind.